Chair frame



FIG. 1 is a front perspective view of a chair frame showing my design;

FIG. 2 is a side elevational view on a reduced scale, the opposite side being a mirror image thereof;

FIG. 3 is a rear elevational view on a reduced scale;

FIG. 4 is a top plan view on a reduced scale;

FIG. 5 is a front elevational view on a reduced scale; and

FIG. 6 is a bottom plan view thereof on a reduced scale. 

The ornamental design for a chair frame, as shown and described. 